I managed to trigger a very interesting bug... :)

[davidfor]

Originally Posted by compurandom

Ok, looking closer, there is a COVER PAGE and COVER IMAGE.

Apparently kepubs require the cover page.

I didn't realize that epubs could have both and just never looked for a cover image when I saw a cover page, but that makes a lot of sense.

That isn't correct. The kepub format does NOT require an XHTML to be marked as a cover. What it states is that the cover image must be in it's own XHTML file, but it doesn't state that this file must exist or how it is found. Experimentation shows that the kepub reader assumes the the first file in the guide is the cover file.

So what I'm looking for is a search in quality check for epubs without a COVER PAGE, where the current search ("cover") presumably checks for epubs without both the cover page and cover image. I assume that if it has a cover page, it also has a cover image.

The existing cover check is only looking at the image.

Epubs without cover pages seem to generate kepubs without cover pages, which do not work properly (unless there is exactly one html/xhtml file).

Sorry, but as I've been stating, that's wrong. The books are working exactly as designed. Your interpretation of this is what I consider to be wrong.

[compurandom]

Originally Posted by davidfor

That isn't correct. The kepub format does NOT require an XHTML to be marked as a cover. What it states is that the cover image must be in it's own XHTML file, but it doesn't state that this file must exist or how it is found. Experimentation shows that the kepub reader assumes the the first file in the guide is the cover file.

Thanks for the clarification of the kepub format.

Sorry, but as I've been stating, that's wrong. The books are working exactly as designed. Your interpretation of this is what I consider to be wrong.

Please be slightly less pedantic? Yes, the kobo is rendering a kepub correctly. No, it isn't rendering it in a way that a epub should be rendered.

Again, I am not saying this is a bug in the kobo, stop being so defensive.
I'm saying this is a bug in either the book or the epub to kepub converter, and which is a debate that is not worth having.

[davidfor]

Originally Posted by compurandom

Thanks for the clarification of the kepub format.



Please be slightly less pedantic? Yes, the kobo is rendering a kepub correctly. No, it isn't rendering it in a way that a epub should be rendered.

I can't decide whether to laugh or at the above. And it's the last sentence that is causing this. A kepub IS NOT AN epub. The rules for epubs are not necessarily the rules for kepubs. Hence, that last sentence is meaningless in the context of this discussion. Or I would add:

... but it is being rendered the way a kepub should be rendered

Again, I am not saying this is a bug in the kobo, stop being so defensive.
I'm saying this is a bug in either the book or the epub to kepub converter, and which is a debate that is not worth having.

Sorry, but you have been as defensive in this as anyone. We have trying to explain how kepubs work and you keep trying to say, well, something else.

As to if there is a bug anywhere, it is in the book. Unless that is the desired behaviour for the book.

[compurandom]

Sorry, but you have been as defensive in this as anyone.

I'm just trying to get fixed what at least two people see as a bug.

Originally Posted by davidfor

The rules for epubs are not necessarily the rules for kepubs.

Agree.

We have trying to explain how kepubs work and you keep trying to say, well, something else.

But we are converting a valid epub and it creates a buggy kepub. You are explaining how kepubs work, and I'm grateful. But the input file is a epub, and the way the kepub works is not how the epub is suppose to work. Inbetween is a bug.

As to if there is a bug anywhere, it is in the book. Unless that is the desired behaviour for the book.

Sometimes the bug is in the epub -- like when the cover page is attached to other things, or when a page is not marked a as a coverpage at all. This is hard to fix and it would be nice if the quality check plugin could flag at least some of these.

Sometimes the bug is in the conversion, where the book does not have a cover page but does have a cover image but the kepub converter fails to create a cover page. If the converter isn't going to create a cover page for this case, then it would be helpful if quality check could flag it.

If the book has no cover at all, quality check can already flag it, and it is questionable if the kepub converter should fix that or not, although calibre already has the ability to generate a cover.

[davidfor]

Originally Posted by compurandom

But we are converting a valid epub and it creates a buggy kepub. You are explaining how kepubs work, and I'm grateful. But the input file is a epub, and the way the kepub works is not how the epub is suppose to work. Inbetween is a bug.

And of course the kepub doesn't work like the epub because it is not an epub and is following the kepub rules.

No bug involved.

Sometimes the bug is in the epub -- like when the cover page is attached to other things, or when a page is not marked a as a coverpage at all. This is hard to fix and it would be nice if the quality check plugin could flag at least some of these.

And none of that is a bug. An epub does not have to have a "coverpage". That means the epub does not have to have an XHTML file marked as "cover". And it does not have to have the cover image displayed anywhere. And the cover XHTML file does not have to display the cover image.

Sometimes the bug is in the conversion, where the book does not have a cover page but does have a cover image but the kepub converter fails to create a cover page. If the converter isn't going to create a cover page for this case, then it would be helpful if quality check could flag it.

Can you please show me in the kepub specs where it says the book must have a "cover page"? Where it says that the cover image must be on a page in the book? It does say that if the cover image is displayed, it should be the only thing in the file. But, none of that is mandatory.

If the book has no cover at all, quality check can already flag it, and it is questionable if the kepub converter should fix that or not, although calibre already has the ability to generate a cover.

Sorry, the whole point of what I have been saying is that the kepub is NOT "buggy". The kepub is behaving EXACTLY as it is supposed to. It is just not behaving how you want it to.

If you want the kepub to behave the way you think it should, then prepare the epub first. Or, use the conversion process rather than the extended driver. Or do an epub-to-epub conversion, or a Polish or use the Modify ePubs plugin to fix the covers.

And the Quality Check plugin doesn't flag if the book doesn't contain a cover. It flags if calibre doesn't have a cover for the book. That means that if you have added a cover to the calibre library, but have not done one of the actions to update the epub with the cover, it isn't going to be there and Quality Check won't tell you. But, you could probably use the "Check no calibre SVG cover" to get close to what you want. Or this plus the "Check non-replaceable cover". Anything that does have a calibre SVG cover will work the way you want it. Anything that doesn't have a replaceable cover is suspect.

And for my curiosity, can you tell me any software that does anything with the XHTML file that is marked as a cover? To the best of my knowledge, nothing does. The calibre editor will set it, and calibre will probably use it if there is no image file marked as a cover when it is getting the cover from an epub. But I have never heard of anything that will do anything with it. Nothing in the Kobo world does. As far as I can tell, everything either looks for the image file marked as a cover, or renders the start of the book and uses the first page.

[compurandom]

Originally Posted by davidfor

Can you please show me in the kepub specs where it says the book must have a "cover page"?

You are completely missing the point. The point is that the books are not functioning the way the user desires. It doeasn't matter where the bug is, if it doesn't function the way the user wants, IT IS A BUG.

I never said that epubs must contain a cover page. I said kepubs must contain a cover page.

The point here is to help the user FIND books with these issues, bug or not, and let the user decide how to fix it.

If you want the kepub to behave the way you think it should, then prepare the epub first.

Yes, exactly, that. My desire here is for as many cases as possible, either have the epub to kepub converter add a cover page, or alternately, have quality check flag epubs that will generate a kepub without a correct cover page so the user can find those and prepare the epubs so they will.

Anything that doesn't have a replaceable cover is suspect.

Just downloaded this: (epub with images)
http://www.gutenberg.org/ebooks/30240

Quality check says it has a replaceable cover.
What it has is a cover image without a cover page.

How would I find this with quality check?

Your suggestions for quality check searches for (non)replacable covers may have turned up some books in my library that still need fixing, but I will have to investigate each one.

And for my curiosity, can you tell me any software that does anything with the XHTML file that is marked as a cover?

I assume you mean other than just displaying it.

I actually don't care if epubs have an xhtml cover page.

What I care about is that kepubs generated from epubs do contain a cover page, and if I can use quality check to search for epubs without one and add one myself to make that happen, I'm ok with that. If the extended driver with kepub conversion inserts it automatically if there isn't one or wraps a cover image in a cover page automatically, I'm very ok with that.

[Terisa de morgan]

In the end, this is reduced too:

• epub and kepub handle cover in different ways
• Quality Check analyzes malformed (or possible PIA) epub
• You want that Quality Check analyze a specific case where a perfectly valid epub could generate a problematic kepub

This is not a bug at any side, it is a feature request for Quality Check epub. (Or, if you want the driver to modify this situation automatically when possible, a feature request for the driver).

A but is when a program doesn't do what it is specified to do, not when it doesn't what the user wants. It can sound pedantic to you, but it is a very very important difference in my world (software design).

[compurandom]

I claim that if the epub has a cover image but not a (marked) cover page, and the extended driver doesn't generate a wrapper cover page during translation, it is a bug, as this is a clear difference between epubs and kepubs that it should fix.

Everything else I agree with you, it's a feature request.

Some preliminary results from my checks...
I used quality check to search for books without a replacable cover.

It found 500 books as follows:
399 either are marked as or are likely to contain only a single xhtml file (will check these later)
101 were left that needed checking

A lot had unmarked covers and after marking the covers, quality check now says they have replacable covers. So, to answer davidfor's question directly: Yes, I found one piece of software at least that uses the cover page: quality check.

I've found two books (I think) so far that even after marking their cover page, quality check says it isn't removable. Perhaps worthy of investigation later, but it's a small number so far so perhaps not.

Some of the epubs with unmarked cover pages were probably originally single html files that calibre split when converting to an epub, and (coincidentally?) split the cover page as a separate file.

Still chewing through the rest...

[jackie_w]

In its current state the 'Quality Check' plugin is unlikely to get any new features as its owner has moved on. This will only change if he returns or if somebody else accepts the non-trivial committment of adopting it.

Modify Epub is in a similar state except a few hardy souls have made small additions without fully committing to be the new 'goto guy'.

I suspect both plugins would benefit from a good overhaul and could be simplified/extended by incorporating the new functionality which now exists in calibre to assist with manipulating epubs (and azw3 and kepub) but which the original creator, kiwidude, didn't have access to.

I'm not criticising anyone for not stepping forward as I don't want the responsibility either. I suspect there are many forked versions of 'Modify Epub' in the wild as people squeeze in their own functionality without having to get to grips with the whole beast.

What might be interesting is if one of the more able developers found it an interesting challenge to create a new framework plugin that handled all the basic functionality but hobbyist Python programmers (e.g. me), could follow some simple rules to create slot-in modules that 'make change X only' and which can be shared, i.e. plugins for the master plugin.

[Terisa de morgan]

Originally Posted by compurandom

I claim that if the epub has a cover image but not a (marked) cover page, and the extended driver doesn't generate a wrapper cover page during translation, it is a bug, as this is a clear difference between epubs and kepubs that it should fix.

And I claim that it is your assumption The plugin doesn't say that the resulting kepub is the same but that you can use the renderer with its features, which you can do

[Terisa de morgan]

Originally Posted by jackie_w

I'm not criticising anyone for not stepping forward as I don't want the responsibility either. I suspect there are many forked versions of 'Modify Epub' in the wild as people squeeze in their own functionality without having to get to grips with the whole beast.

I totally confirm it (my own version add some functionalities I like.. and others I've never been able to do it work... because it would require too much time and I'm not interested )

[compurandom]

Ok, completed the survey of my library trying to use quality check / replaceable covers to find books missing cover pages. Stats are:

Of the 101 I checked that contained more than a single xhtml file:
90 had unmarked coverpages which are now marked.
2 need a cover page added
5 were single files I hadn't yet marked as such

After marking all the valid cover pages I found in the rest:
6 match "non-replacable cover" (and don't match replacable cover obviously)

These numbers would be higher if I hadn't spent the last 2 months adding cover pages.
Most of the ones I added pages to already had cover images, although I probably created covers for a lot of them as well.

I currently have 21 epubs in my library I've marked as needing cover pages added.
I'll check them for other formatting issues while I'm adding cover pages. At a glance, it looks like I also generated calibre covers for most of those.

[JSWolf]

Originally Posted by Terisa de morgan

I totally confirm it (my own version add some functionalities I like.. and others I've never been able to do it work... because it would require too much time and I'm not interested )

What added functionality did you add to Modify ePub? Thanks.

[compurandom]

I use modify epub occasionally to fix epubs. I wish it did a better job of removing javascript from epubs. But in general I find polish epub to do a better and simpler job.

I'm in the middle of digging into gnome shell extensions right now or I'd start looking at modify epub and quality check. Maybe in a few weeks I can look into it.

Maybe it would be interesting to start a new thread for people to collect what features they'd like added (or have already partially written) for modify epub and quality check.

[Terisa de morgan]

Originally Posted by JSWolf

What added functionality did you add to Modify ePub? Thanks.

Some related to jacket position (it works), tocs (so so) and covers (still pending).